Github Actions Setup (#1)

* add odoc github action

* add write permission for odoc workflow

* only build pages on main

.github/workflows/odoc.yml

@@ -0,0 +1,24 @@
+name: Deploy odoc
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  deploy-doc:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - name: Checkout tree
+        uses: actions/checkout@v3
+
+      - name: Set-up OCaml 5.0
+        uses: ocaml/setup-ocaml@v2
+        with:
+          ocaml-compiler: "5.0"
+          dune-cache: true
+
+      - name: Deploy odoc to GitHub Pages
+        uses: ocaml/setup-ocaml/deploy-doc@v2